Typewriting machine



' April 23, 1935. H. PITMAN 1,998,789

TYPEWRITING MACHINE Filed Aug. 7, 1931 s Sheets-Sheet 1 bran/0r:

April 23, 1935; H. L. PITMAN 1,993,789

TYPE-WRITING MACHINE 7 Filed Aug. 7, 1931 3 Sheets-Sheet 2 Ap 23, 1935- v H. L. PITMAN 1,998,789

TYPEWRITING MACHINE Filed Aug. 7, 1951 s Sheets-Sheet :5

Federated Apr. 23, 1935 UNITED- STATES TYPEWBITING MACHINE Henry L. Pitman, Westileid, N. 1., assignor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application August 7, 1931, Serial No. 555,699

15 Claims.

The present invention relates to noiseless typeactions for typewriting machines.

A floating connection is provided between the key-lever and its type-bar, by means of suitable toggle-connections. The initial depression of the type-key drives the printingtype towards the platen, while the final portion of the keystroke tends to slow down the type-bar immediately in front of the platen. The final part of the key-depression operates to press the type firmly but silently against the platen. 1 I

A toggle in the type-linkage becomes straightened out when the key has been moved about three-quarters down; and for the last quarter of the stroke of the key this straightened toggle, supported by a second toggle, acts as a rigid link, which is moved by a floating link supported, preferably slidably, at one end for fore-and-aft movement, and connected at the other end to a lever that is connected to the key-lever in a manner to tarded movements from equal increments of key-- key is near the end of its typing stroke, and when lever movement. By this means the'type is pressed against the platen with a force determined by the pressure on the key. The lever, to

-which one end of the floating link is connected, may have an arm that serves as one member or the supporting toggle.

The floating link provides a movable fulcrum, or, in other words, a movable point of reaction for one end of the first toggle, the other end of which is connected to the type-bar at a point near the type-head. In order that this toggle may efliciently perform its function of checking the movement of the type-bar, said fulcrum or point of reaction is disposed on the floating link at a point close to its slidingly supported end. Thus, the reactiomtransmitted through this toggle in checking the type-bar, is mainly upon the sliding support of the floating link.

In the present invention the usual standard type of Underwood key-levers and. bell-cranks connected thereto may be used. The bell-cranks are connected by pin-and-slot connections to a second set of bell-cranks, which constitute the above-mentioned levers to which the floating links are connected and which may be mounted arouately on the type-bar fulcrum-rod of the standard Underwood machine. The universal bar and escapement-mechanism may be mounted and oper ated in the usual manner by this second set of bell-cranks. The type-bars themselves are shorter than the standard Underwood type-bars and are mounted on an auxiliary fulcrum-rod in the same segment and concentric with the first fulcrum-rod. The present-type-action is constructed to permit, it to be readily attached to a standard Underwood machine with a minimum of alteration. Auxiliary to said segment is another segment spaced forwardly thereof for slidably supporting the arcuately arranged floating links.

Other features and advantages will hereinafter type-action, at the middle of the segment, in its position of rest.

Figure 3 is a perspective skeleton layout of the same middle type-action in its typing position. Figures 4 to 6 are simplified views similar to Figure 2, showing, respectively, the middle typeaction when its key is half depressed, when the the type-action is in typing position.

Depression of a type-key ill swings a key-lever Ii about a fulcrum-rod i2 and, through a pinand-slot connection l5, ll, vibrates a driving-bellcrank lever l'l about a fulcrum-rod It.

This movement of the bell-crank I1 is transmitted through a pin-and-slot connection 26, 21, to the slotted rear arm of an accelerating-retarding bell-crank lever- 28, pivoting about an arcuate fulcrum-wire 29, concentric with the usual point just below the printing point. The slot 27 is curved so as to produce an easy initial key-action, a successively positive and negative acceleration of movement of the bell-crank lever 28 during substantially the first three-quarters of the keystroke, and a retardation of movement of said lever 2| during the last quarter of this stroke.

The movement of the lever 28 thus effected is transmitted from the front arm of said lever 28 to a swingingtype-bar 81, partly through a system of two toggles a, 34 and 35, 36 which are straightened out by this rotation of the bell-crank 2!, so as to lift the type-bar 31 from its horizontal .cumbent position of rest to its vertical printing position and partly through. a connecting-rod 38, the small end of whichis eccentrically mounted on a'crank-pin 8! on the bell-crank 28, while its reciprocating head '51 embodies a movable fulcrum for the toggle 85, 36.

The initial depression of the key l0 thus drives type 84 carried by the type-bar rapidly towards a platen 1i, while the final p02- tion of the key-stroke tends to slow down the typebar 31 immediately in front of the platen, and to press the type 64 firmly but silently against the platen, due to the combined action of the curved slot 21 and of the connecting-rod 38, which then positively pulls the straightened-out toggle 35, 36 towards the platen 1 I.

Between the two side walls I8 of the frame 20 of the machine is secured a one-piece bearing 2| for the fulcrum-rods I2 and I8, having two rows of open slots 22 and 23 cut crossways of the two bars forming said bearing opposite each keylever II and bell-crank I1, respectively.

The key-levers I I are disposed in parallel planes and spaced ofl'at their rear ends by the slots 22, while a front comb 24 fixed to the side walls l9 of the frame 2|! provides a forward guide for the up-and-down movement of the keys. The upward return movement of the key is limited by a fixed stop-cross-bar 25.

The upstanding arms of the bell-crank levers |1 gradually increase in length towards the sides of the machine (Figure 1), and, progressing outwardly from the middle of the system, said arms are offset or fanned inward more and more at 30, so that the upper inwardly-bent ends 3| of these arms are radially arranged to correspond with the arcuate and radial arrangement of the accelerating bell-crank levers 28.

The type-bar segment 32 is secured by means of screws 4| t6 inwardly-projecting flanges 42 fixed to the side walls I8 by rivets or screws 43.

The outer portion of this segment 32 is thick ened at 44, and has grooves 45 cut across the front face thereof that radiate from a common point at or near the typing center of the machine. The front face of the segment 32 is further provided with an arcuate slot 46 to receive a curved fulcrum-wire 41 secured therein in the usual manner. A type-bar 31 is mounted within each groove 46 to pivot upon the wire 41 with a working fit, so as to provide'for a free swinging movement of the bar.

A rib 48 of the segment 32 is slotted so as to form a guide-comb for levers 28, and is provided with a rear arcuate slot 48 to receive the fulcrumwire 28.

A front segment-bar 5| is secured by screws 52 to supports 53, projecting forwardly from the flanges 42. This segment 5| is slotted around its periphery at 54 to receive an arcuate wire 55, and radially at 58 to support the forked ends 81 of the connecting-rods 38, which reciprocate upon said wire 55 and are laterally guided within said slots 66.

Each of said forked ends 51 presents'an offset portion 58 on which is secured the movable fulcrum 48 of the toggle 35, 38. The lower end of the link 35 of said toggle is held on said pivot 48 by means of a flat spring 58 riveted at 80 on the connecting-rod 38.

.To the supports 83 is also secured a segmentcomb 8|, with resilient fingers 62 acting as a rest for the connecting-rods 33 and also as a limiting stop for the return movement of the type-bars 31.

Each type-bar 31 carries at its outer end an offset head 83 carrying two types 64, and is similarly offset or bent rearwardly at its inner pivoted end 85, so as to fit In a groove 48 and to take a vertical position close to the central part of the segment 32 in its printing position (Figure 3).

The momentum of the-head 83 is minimized during the swinging movement of the type-bar 31, sinoethe latter is made short, and a pivoted connection 66 between said bar and the link 36 is arranged as close as possible to said head 63.

The link 35 is provided with an offset 61 carrying a pivot 68 connecting the two toggles 33, 34 and 35, 36 together. When said toggles are straightened out (Figure 5) this offset 61 is about midway between the pivots 40 and 66 and in such relative position with respect to the fulcrum 29 that the toggle 33, 34 is then about perpendicular to the toggle 35, 36. To stabilize the type-heads 63 at the instant of the type-impression, a stationary type-guide 69 is centrally secured by screws 10 on top of the segment 32 in front of the platen 1|.

This platen 1| (Figure 2) is supported in a carriage 12 to travel back and forth upon rails 13 .(only one of which is shown).

Said carriage 12 is controlled by escapementdogs 14 and 15 mounted upon a dog-rocker 16 pivoted at 11.

The dog 14 normally engages with the teeth of an escapement-wheel 18 having a one-way connection with a pinion 18 meshing with a rack 88 supportedon the typewriter-carriage 12. To actuate the dog-rocker 16 an arcuate universal bar 8| is pushed rearwardly against the action of a spring 82 by heels or bosses 83, formed, on the accelerating bell-crank levers 28, as the typebars 31 swing upwardly and rearwardly against the platen. The universal bar 8| is carried by a frame 84 extending rearwardly and pivotally supported at its rear end at 85 upon two arms 86 of a rocking frame pivoted at 81 to the main frame 20.

The frame 84 is provided with a cross-bar 88 to engage the dog-rocker 16, so as to disengage the dog 14 and shift the dog 15 into engagement with theescapement-wheel 18. As soon as the return stroke of a type-bar 31 starts, the universal bar 8| and dog-rocker 16 are almost instantly returned by spring 82, while at the same time said spring 82 acts as a starting pusher upon the heelor boss 83 of the bell-crank 28, so as to help the return spring I3 in breaking the lock of the toggle 35, 38 in its aligned or stretched condition, shown in Figures 3 and 6, to permit free and quick return movement of the type-bar 31.

In the normal rest position of each type-faction, the key-lever II is held against the stop 25 by spring l3, andthe type-bar 311s supported in an almost horizontal position between the two segments 32 and 5| by the two toggles 33, 34 and 35, 36, then in collapsed condition and folded in opposite direction, and the connectingrod 38 rests upon the stop 6|, 62, the crank-pin 39 being then in its lowermost position (Figure 2).

It will be seen that when a key I0 is depressed toirock its lever II about the fulcrum I2, the driving bell-crank I1 vibrates about its fulcrum I8, while the stud 26 engages the curved slot 21 at the bearing point most distant from the inicrum 28, and during about the first half of the key-stroke the stud 26 rises into said slot until it intersects the vertical plane passing through its fulcrum I8, and co-operates withv the bellcrank 28, so as to transmit to the type-bar 31 a well-known form of accelerating motion, providing an easy initial movement of the key-' lever to convey motion to the train of initially inert parts '33 to 38 The rocking of the arm 33 of said bell-crank 28, which arm constitutes at the same time the lower link of the intermediate toggle 33, 34, spr a S Sim ltaneously said toggle and the lifting toggle 35, 36, thereby causing the type-bar 31 to be lifted at accelerated speed.

The connecting-rod 38, which ties the movable fulcrum 40 of the lifting toggle 35, 36 to the crank-pin 39, assists said movement of lifting the type-bar by slightly removing the fulcrum 30 away from the fulcrum 41 during the rightward stroke of its reciprocal movement.

The normal position of rest of the key l and the type-bar 31 being respectively A and a (Figure 4), the type-bar will describe an are from a to b of about 13 degrees during the first quarter of the downward travel of the key from A to B and an arc of about 59 degrees from b to 0 during the second quarter of the key-travel from B to C.

Soon after the key has passed its middle position C, the stud26 passes the aforesaid vertical planethrough itsd'ulcrur'n l8 and moves downward within the slot 21, away from the fulcrum 2-9. The bell-crank 28 therefore from now on has a negative accelerating action, so that when the key passes from C to D during the third quarter of its travel, the type-bar describes an are from c to d of-about 20 degrees.

When the key is depressed three quarters of its stroke in this position D,'the two toggles 33, 34 and 35, 36 are almost straightened out, the type-bar is at about 2 degrees from its typing position, having already described an arc of about 92 degrees, and the bell-'crank'23 is ready to start its retarding action.

During the last quarter of the travel of the key from D to F, the two toggles 33, 33 and 35, 36 are first simultaneously straightened out by the combined action of the bell-crank 28 and of the connecting-rod 33, which describes now the leftward stroke of its reciprocal movement, the key being then in the position'Eand the type-bar in the corresponding position e (Figure Then the toggle 33, 33 is overthrown slightly beyond its dead-center line 83, while the toggle 35, 33 remains rigid and extends substantially straight along its dead-center line 60, its fulcrum 40 being then pulled in the direction of the arrow 9| (Figure 6) by the crank-pin 39 through the connecting-rod 33 synchronously pressure of the type 64 upon the work-sheets,

according to the number of these shets, without necessarily having to readjust the platen forwardly. This is due to the fact that the typebar, at the printing point, is responsive to the degree of pressure applied on the key, the pressure of the type not being dependent entirely on the momentum of the parts of this type-action as they bring the type-bar from cumbent to printing position. Furthermore, the bell-crank 23 near the end of the stroke of the type-bar has a lever ratio which multiples the force delivered by the bell-crank l1 and imparted to the connecting-rod 33.

The arrow 92 (Figure 6) indicates a component ofthe printing pressure along the toggles 35-36. It will be noted that the action on the upper type 64 is substantially the same as on the lower type, when the platen is case shifted.

The type-bar performs the printing operation partly by this manually controlled pressure positively transmitted to the type, and partly by the impact due to the reduced momentum left in the. type-bar and its connections at the end of the printing stroke, this momentum varying with the speed and quality'oi' touch of the operator.

A layer of soft material 93 is provided around the stop 25. The connecting-rod 38 normally rests on theresilient fingers 62.

It will be noted. that the type-actions of the present invention are controlled from a standard keyboard with a single case-shift (not shown), and may be applied'to a standard Underwo'od typewriter without changes in the platen-carriage and associated parts, the escapement-mechanism, the key-levers H and the driving-bell cranks l1, and with very few changes in the main frame thereof.

Each type-bar, its two connecting toggles, and the corresponding connecting-rod 33 and bellcranks 28, are assembled so as to form a stockunit, which with the other units may be readily assembled radially on the segment 32. The whole thus formed may then be easily inserted in the frame 26, adjusted in position with respect to the platen, the universal bar 3| and the bellcrank levers l1, and then secured to the flanges 42 of said frame by means of two screws II. The front segment 5|, already provided with its arcuate wire 55, receives the forked ends 51 of the links 33 and is secured by means of screws 52 to the supports 53 extending forwardly of the flanges 42 and serving also to carry the segmentcombil.

The key-levers and the driving-bell-crank levers i! are arranged in the usual parallel array according to the standardspacing of the keyboard.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim l. In a type-writing machine, a type-action comprising, in combination with a platen and a frame, a key-actuated accelerating-retarding bell-crank lever, a swing type-bar, a toggle pivotally connected at one end to said type-bar, a link connecting the end of the driven arm of said bell-crank lever to the elbow of said toggle, a tie-piece connecting the opposite end of said toggle to a crank-pin carried by said bell-crank lever, said tie-piece being provided with a forked end, and a guiding support carried by said frame in which said forked end may reciprocate.

2. In a typewriting machine, a type-action comprising, in combination with a platen, a depressible key, a key-lever, a driving bell-crank lever, an accelerating-retarding bell-crank lover, a pin-and-slot connection between said two levers with a slot cam-shaped so as to provide for positive acceleration of motion during substantiallythe first half of the downward travel of the key, for a negative acceleration of motion during substantially the third quarter of said travel and for a retardation of motion during the last quarter of said travel, a connecting rodeocentrically mounted on said accelerating-retard ing bell-crank lever, 11. power-transmitting articulated system fulcrumed to the head of said connecting rod and'pivotslly connected to said ac.-

celerating-retarding bell-crank lever, and a swinging type-bar pivotally connected to the last link of said articulated system.

3. In a typewriting machine, a type-action comprising, in combination with a plate'n and a segment, a depressible key, a key-lever, a driving bell-crank lever, an accelerating-retarding bellcrank lever with a front arm and a rear slotted arm, a reciprocating connecting rod eccentrically mounted on said accelerating-retarding lever, a power-transmitting toggle-system fulcrumed to the head of said connecting rod and. pivotally connected to said fro'nt arm, and a swinging type-bar pivotally connected near its type-carrying head to the last link of said toggle-system and fulcrumed at its other end to d segment.

4. In a typewriting machine, in combination with a frame carryinga segment and a platen, a depressible key, a key-lever and a driving bellcrank lever pivoted on said frame, an accelerating-retarding bell-crank lever anda type-bar pivotally mounted in said segment, a crank-pin secured to said accelerating-retarding lever, a connecting rod pivotally mounted on said crankpin at its small end and provided with a pivot at its head, and an articulated system of linkages fulcrumed on said pivot and connecting mechanically said accelerating-retarding lever and said 5. In a typewrlting machine, in combination with a platen and a radially-slotted segment, a depressible key, a key-lever, a driving'bell-crank lever with a longarm provided with a pin, an accelerating-retarding bell-crank lever with an arm provided with a cam-shaped slot co-operating with said pin, a reciprocating connecting rod eccentrically mounted on said accelerating-retarding lever, an intermediate toggle, one link of which is formed by the other arm of said accelcrating-retarding lever, an operative toggle fulcrumed to the head of said connecting rod and pivotally connected to the other link of said operative toggle, and a swinging type-bar pivotally connected near its type-carrying head to the driven link of said operative toggle.

6. In a typewriting machine, in combination with a traveling platen and a fixed frame, a depressible key, a key-lever, a driving bell-crank lever co-operating with an accelerating-retarding bell-cranklever, a swinging type-bar, a toggle operative to swing said type-bar to type when said key is depressed, a movable fulcrum-pivot for said toggle, another toggle, one link of which forms at the same time the front arm of said accelerating-retarding lever, to drive the firstmentioned toggle, a rear segment readily secured to said fixed frame and forming a one-piece bearingand radial guide for said type-bar and said accelerating-retarding lever, an auxiliary front segment readily secured to said fixed frame, a tie-piece eccentrically mounted on said accelerating-retarding lever at one end, and guided in said auxiliary segment at its other forked end, an oi'fsetboss vof said forked end carrying said movable fulcrum-pivot, and an arcuate resilient stop, secured to said fixed frame, upon which rests normally said tie-piece.

7. A noise-reducing type-action for typewriting machines comprising, in combination with a revoluble platen and a fixed frame, a radially grooved and slotted segment removably secured to said frame, a swinging type-bar pivoted and guided in one groove 'of said segment, key-actuated power-transmitting means including a key- 1eve'r,'pivoted to said frame,- and an acceleratingretarding bell-crank lever, pivoted and guided in one slot of said segment, for swinging said typebar to printing position, said power-transmitting means including furthermore a driving toggle actuated through a link by said acceleratingretarding lever and mounted on the head of a reciprocating connecting rod driven by said same lever so as to positively pull said driving toggle toward said platen during the typing with a minimum of noise.

8. A noise-reducing type-action for typewriting machines comprising, in combination with a fixed frame, a revoluble and traveling platen and an escapement mechanism controlling the travel of said platen, a radially grooved and slotted segment removably secured to said frame, a swinging type-bar pivoted and guided in one groove of said segment, key-actuated power-transmitting means lncludinga key-lever, pivoted to said frame, and an accelerating-retarding bell-crank lever, pivoted and guided in one slot of said segment, for swinging said type-bar to printing position, said power-transmitting means including furthermore a driving toggle actuated through a link by said accelerating-retarding lever and mounted on the head of a reciprocating connecting rod driven by the same lever so as to positively pull said driving toggle toward said platen during the typing with a minimum of noise, a

type-action return spring, and means controlled by the universal bar of said escapement mechanism assisting said spring to break the lock of this driving toggle almost instantly when the. key is released after typing and to restore very quickly all the moving'parts of the type-action to their respective normal positions of rest.

9. In a front-strike typewriting machine, a type-action including, in combination with a platen; a key-actuated lever fulcrumed below the printing point and having an arm extending towards said printing point, a bell-crank lever fulcrumed at a point between said printing point and the path of the swinging end of said arin, said bell-crank ,having an arm connected to said arm of the key-actuated lever by a connection effective in conjunction with the arrangement of the key-actuated lever and bell-crank lever to first accelerate and finally retard the movement of said bell-crank upon equal increments in the movement of the key-actuated lever, a swinging type-bar connected to said bell-crank through a toggle-system having a floating fulcrum, and a connecting rod pivoted at one end to a crankarin of said bell-crank, saidrod extending forwardly from said crank-arm, and having its forward end guided by a support, for pivotal and endwise movement of the rod relative to said support, said fulcrum being at a point on said rod close to said support.

I 10.111 9. front-strike typewriting machine, a

type-action including, in combination with a platen; a key-actuated lever fulcrumed below the printing point and having an arm extending towards said printing point, a bell-crank lever fulcrumed at a point between said printing point and the path of the swinging endof said arm, said bell-crank having an arm connected to said arm of the key-actuated lever by a connection efi'ective in conjunction with the arrangement of the key-actuated lever and bell-crank lever to first accelerate and finally retard the movement of said bell-crank upon equal increments in the movement of the key-actuated lever, a swinging type-bar, a normally folded toggle having one member pivotally connected to saidtype-bar, a

horizontal connecting rod slidably mounted at its forward end and connected at its rear end to said bell-crank, the other member of said toggle being pivoted to said connecting rod and a link pivoted at one end to said other toggle-member, said link being connected at its other end to a second arm of said bell-crank to form a normally folded toggle therewith operative to swing said other toggle-member to unfold and straighten the first toggle for swinging the type-bar from cumbent position almost to the printing point, said levers, toggles, and connecting rod cooperating then to impart a powerful pressure to said type-bar by reason of the retarded movement of said bell-crank imparted to said connecting rod. i

11. In a front-strike typewriting machine having a fixed frame, a traveling platen and a standard keyboard, in combination with'the keys of said keyboard, a main segment removably secured to said frame, series of parallel key-levers and driving bell-crank levers pivoted to said frame, series of arouately-arranged acceleratingretarding bell-crank levers and swinging typebars pivoted to said main segment, said latter bell-crank levers being connectible to corresponding driving bell-crank levers by pin-and-slot connections, said driving bell-crank levers having a common fulcrum-axis, and also having arms of graded lengths and bends to reach to the armately-arranged accelerating-retarding bell-crank levers, an auxiliary segment removably secured to and in front of said main segment, a series of arcuately-arranged connecting-rods slidably supported at one end in said auxiliary segment and extending rearwardly for connection to the armately-arranged bell-crank levers, and arcuatelyarranged toggle-systems reacting against said connecting-rods and operable by said accelerating-retarding levers, to first swing said type-bars almost to the printing point as limited by the straightening of the toggles, the type-bar-printing movement'being completed by endwise movement of said connecting-rods, each type-bar with its controlling accelerating-retarding lever and the intermediate linkages for forming a stockunit, which may be readily mounted in radial slots provided therefor in the main segment, said latter forming a provisional carrier or holder for all type-bars, toggles, connecting-rods and accelerating-retarding levers, which may be easily inserted as a whole in the machine and secured to the frame thereof.

12. In a front-strike typewriting machine, a type-action comprising, in combination with a platen; a key-actuated bell-crank lever, a swinging type-bar, a toggle having members normally folded with. the cumbent type-bar, one togglerod near the forward end of the latter, the rear end of said connecting-rod being pivoted to a crankarm presented by said bell-crank lever.

13. In a typewriting machine, a type-action comprising, in combination with a platen, a keylever, a bell-crank lever connected to said keylever by a motion accelerating and retarding connection, a connecting-rod having one end pivoted to a crank on the bell-crank lever, the other end of said connecting-rod being slidably suported, a swinging type-bar, and normally folded power transmitting instrumentalities pivoted to and reacting against said other end of said connectingrod and pivotally connected to said acceleratingretarding bell-crank lever, and to said swinging type-bar, said instrumentalities, in being unfolded by means of the bell-crank-lever movement, imparting a limited movement to the typebar sumcient to bring the type-bar almost to the printing point, further movement of the bellcrank and connecting-rodbeing effective to bringsaid type-bar to print.

14. In a typewriting machine, in combination with a platen and a fixed frame; a key-lever, a bell-crank lever having an accelerating-retarding connection to said key-lever, a swinging type-bar, a toggle normally folded with said type-bar and operative while being unfolded to swing said typebar almost to typing position, a movable fulcrumpivot for said toggle, another toggle to drive, unfold and support the first one,-one member of said other toggle being formed by an arm of said accelerating-retarding bell-crank lever, and a connecting-rod embodying said fulcrum-pivot, said connecting-rod pivoted to and operable endwise by said accelerating-retarding bell-cranklever after said toggles have been, straightened, to complete the movement of said type-bar to type, the connecting-rod being slidably guided at one end in said frame.

15. In a front-strike typewriting machine hav-- ing a platen, the combination with a type-carrier swingable from cumbent to printing position and a key-lever therefor, of a driving bell-crank lever actuated by said key-lever, a bell-crank lever having one arm connected to said driving lever by an accelerating-retarding, pin-and-slot connection, a driving toggle, connected to and normally folded with the cumbent type-bar, said toggle react ing against a floating fulcrum and having a link- ,connection with another arm of said acceleratingretarding lever so as to be straightened out to bring the type-carrier almost to the printing point by the depression of the key-lever, and a connecting-rod which affords said floating fulcrum and extends therefrom for connection at one end to the acceleratingrretarding lever, said connecting-rod slidably guided at its other end by a fixed bearing, said connecting rod acting by its endwise movement to drive said toggle, held in substantially rigid, straightened-out condition, to complete the printing movement of the typecarrier. HENRY L. PITMAN. 

